As far as I'm aware, China has been giving loans to various countries in Africa and building infrastructure in exchange for money and maybe some stuff like recognizing Taiwan as part of China. But why do people say China is imperialist for doing this? Is there truth to it or is it another strain of radlibs eating state department propaganda?
It's also because US debt is a really solid investment, and if your trading partner is getting rich through trade with you it makes sense to buy into their success.